python-openstackclient uses since some time publish-openstack-docs-pti
which uses openstack-tox-docs template - and not anymore
build-openstack-sphinx-docs.
Update cross-osc-build-sphinx-docs and rename to cross-osc-tox-docs so
that the same job is tested here that is ruuning in osc.
Change-Id: I9d6cefbc92cb8434d32c3ac0369ef49bc0ef4468